Dyfyniad APA

Aker, H. F., Nelson, D. L., & Aker, V. N. (1936). Yesterday: The foundation of today. Harr Wagner Pub. Co..

Dyfyniad Arddull Chicago

Aker, Homer Ferris, D. Lloyd Nelson, and Vanza Nielsen Aker. Yesterday: The Foundation of Today. San Francisco: Harr Wagner Pub. Co., 1936.

Dyfyniad MLA

Aker, Homer Ferris, et al. Yesterday: The Foundation of Today. Harr Wagner Pub. Co., 1936.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.